Well, in 'percy becomes a killer fanfic', it could be that Percy is cursed. This curse could slowly corrupt his mind, making him see his friends and allies as enemies. As a result, he begins to hunt them down one by one. It might also be that he is tricked into believing that killing is the only way to save the world he loves, so he takes on the role of a killer with a false sense of heroism.
Perhaps Percy is pushed to his limits by some great injustice in the story world. Maybe he witnesses the death of someone he loves at the hands of an evil force. This trauma could transform his personality, leading him to become a killer with a vendetta. He might start by targeting the ones directly responsible and then expand his scope as his thirst for vengeance grows.
In this fanfic, Percy could be brainwashed by a powerful and malevolent entity. The entity could manipulate Percy's memories and emotions, turning him into a cold - blooded killer. He might lose all sense of his former self and engage in brutal killings without any remorse. His journey could then be about breaking free from this brainwashing and trying to atone for the deeds he has done while under the influence.
It could be an ancient and powerful god who has long been plotting against Percy. This god might be jealous of Percy's power and popularity, so he devises a plan to turn Percy into a killer, knowing that it will lead to Percy's downfall and his own rise in power.
In this fanfic, Percy might be seen as an outcast at first among the Avengers because he's so different. But as time goes on, they come to respect his abilities. The story could also explore how Percy's presence affects the dynamics within the Avengers. Does he create new rivalries or alliances? And how does he adapt to their high - tech world when he's used to the more ancient and magical world of the Greek gods? Maybe he even tries to introduce some of his own magic into their technology, leading to some interesting and unexpected results.
Well, perhaps Percy discovers some ancient power within himself that gradually transforms him into a god. He might have to face a series of trials to fully ascend, like battling powerful monsters or making difficult moral choices.
Another idea is that Percy discovers he has a long - lost vampire heritage. As he becomes a vampire, he starts to unlock memories and powers related to his vampire lineage. He could go on a journey to find out more about his vampire ancestors and the secrets they held, all while adjusting to his new vampiric existence which is full of both challenges and newfound abilities.
Maybe Percy discovers a hidden garden and becomes obsessed with it. He starts to learn about different plants, takes care of them, and the garden becomes his special place.
Maybe Percy has been through a great betrayal, like his closest friend turned on him for power. So he starts to close off his emotions to avoid being hurt again.
A possible plot could be that Percy has a personal experience that makes him want to become a police officer. Maybe he witnesses a crime and feels helpless. So, he decides to take matters into his own hands. During his training, he befriends some fellow trainees, and together they form a tight - knit group. Once on the job, they are given a cold case to solve. Percy uses his unique perspective and determination to crack the case, which had been baffling the department for years. This earns him the respect of his colleagues and the community.
Well, one possibility is that Naruto could be framed for a crime he didn't commit and then be forced to go on the run. In the process, he might have to kill in self - defense. As he gets more and more hunted, his views on killing could change. Another idea is that he's exposed to some dark ninja art that corrupts his mind and makes him see killing as a means to an end, like achieving peace in a very twisted way.
There could be an old gardener who mentors Percy. The gardener might teach Percy all about the plants in the garden, their needs, and how to keep the garden thriving.
In this fanfiction, Percy could be an assassin who is on a quest to find a powerful artifact. This artifact was stolen by a rival group and is being used for evil purposes. He travels across different lands, using his assassin skills to gather information, fight off enemies, and finally retrieve the artifact to save the world.